Microminerais orgânicos em dietas para poedeiras comerciais

• Autor(a) principal: Stefanello, Catarina
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Estadual de Maringá (RI-UEM)
• Texto Completo: http://repositorio.uem.br:8080/jspui/handle/1/1774
• topic: Poedeiras comerciais; Cobre; Suplementação; Manganês; Zinco; Proteinatos; Ovo; Qualidade; Casca do ovo; Ultra-estrutura; Brasil.; Laying business; Copper; Supplementation; Manganese; Zinc; Proteins; Egg; Quality; Eggshell; Ultrastructure; Brazil.; Ciências Agrárias; Zootecnia

The effect of dietary supplementation of different levels of trace minerals was evaluated on the productive performance, eggshell quality and ultrastructure of the eggshell of commercial laying hens. This study was carried out with the objective of evaluating the effect of supplementation of trace minerals manganese (Mn), zinc (Zn) and copper (Cu) on the productive performance and egg quality of the birds. Three hundred sixty Hy-Line W36 laying hens from 47 to 62 weeks of age were used. The experimental design was completely randomized, compound by nine treatments, five replicates and eight birds per experimental unit. The treatments consisted of a control diet without supplementation of trace minerals Mn, Zn and Cu; four supplementation levels of these minerals in inorganic form, and four levels of supplementation of these minerals in organic form (proteinates). The supplementation levels in mg/kg of Mn, Zn and Cu, were, respectively, 35-30-05, 65-60-10, 95-90-15, and 125-120-20. The supplemented diet with minerals in organic form did not affect (P>0.05) the feed intake, egg production and feed conversion (kg/dz and kg/kg), specific weight and Haugh unit of eggs. However, there was a quadratic effect (P<0.05) of the levels of trace mineral supplementation on average egg weight and egg mass, with no difference between the sources of trace minerals. There was a linearly reduction (P<0.05) in the percentage of loss of eggs and a linearly increase (P<0.05) in the breaking strength and in the percentage of eggshell. The effect of the mineral source was evident in the lower loss of eggs, higher thickness and increased strength of the shell for the treatments that were supplemented with the organic source used in the form of proteinates. There was effect (P<0.05) of the source and supplementation levels for total thickness, thickness of palisade layer and number of mammillary buttons in the shell. The best results were obtained with the supplementation of organic source, as it provided quadratic effect (P<0.05) of the total thickness and of the palisade layer and linearly reduced (P<0.05) the number of mammilary buttons in the shell. The increase of the supplementation levels of Mn, Zn and Cu provided quadratic increase (P<0.05) in the percentage of palisade and mammillary layers, but it did not differ regarding the mineral supplemented source.